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INTRODUCTION <br />The original (proposed) location for Pond 005 was submitted to Colorado Mined <br />Land Reclamation Division (CDMLR), now known as Colorado Division of <br />Reclamation, Mining and Safety (CDRMS), on November 9, 1990 as part of Permit <br />Revision No. 1. Subsequently, in a memo dated May 23, 1991 from Bruce Stover <br />to Larry Routten, a number of concerns were raised regarding land stability in <br />the north mining block. There concerns prompted CMLRD to issue approval of PR <br />#1 with certain stipulations. In brief, Stipulation No. 17 required Seneca <br />Coal Company (SCC) to revise its design, complete land form mapping, and <br />include plans for geotechnical monitoring. Please see Proposed Decision and <br />Findings of Compliance for the Seneca II-W Mine, Permit C-82-057, Permit <br />Revision No. 1, September 4, 1991 for complete discussion regarding the <br />stipulation. <br />That stipulation prompted SCC to contract the services of John Ivey of Amuedo <br />and Ivey, Inc. to map and investigate the landforms near the proposed <br />facilities, and Dick Suedkamp of Ground Engineering Consultants, Inc. to <br />investigate the geotechnical stability of the area and assist in the <br />embankment design. There reports can be found in Attachments 13-3A and 13-3B. <br />SCC conducted the hydrology and sedimentology portions of the pond design. <br />This information is presented in Attachment 13-3. As a result of these <br />investigations, the final location for Pond 005 is shown on Exhibit 13-2, <br />Surface Hydrology, and described as located in the NW1/4SW1/4 of Section 10, <br />Township 5 North, Range 88 West in a tributary to Dry Creek (referred to in <br />some sections of the report as Pond 005 Gulch). <br />Sediment Pond 005 was designed and constructed in accordance with the criteria <br />set forth in Rule 4.05.6. The primary function of the pond is to control <br />sediment from the mine disturbance area. Surface runoff not requiring <br />treatment is diverted around the pond. According to the definition of a <br />sedimentation pond (Rule 1.04(115)), this structure does not meet either the <br />State Engineer's requirements or those set forth by MSHA. <br />The embankment for Pond 005 was design in accordance with Rule 4.05.6(11). <br />Due to the saturated condition of the foundation at least part of the year, <br />the embankment was constructed with a horizontal drainage system. A toe drain <br />was installed that will collect the water and discharge it below the toe of <br />the embankment. This system is designed to act as controlled seepage through <br />the embankment. <br />Although a temporary impoundment, the pond and embankment were constructed to <br />the prescribed standards for a permanent impoundment structure. The primary <br />TR-59 13-3C-1 Revised 05/07 <br />